Beirut: Syrian government shelling and offensives against rebel-held towns killed at least 43 civilians across the country on Saturday, activists said, as the US posted online satellite images of troop deployments that cast further doubt on whether the regime intends to comply with an internationally sponsored peace plan.

Syrian President Bashar Assad has accepted a cease-fire deadline brokered by international envoy Kofi Annan, which calls for his forces to pull out of towns and cities by Tuesday and for both government and rebels to lay down their arms by 6 am local time Thursday.

But the escalating violence of the past few days has fueled accusations that Assad is rushing to stamp out as much of the year-old uprising against him as he can before next week's cease-fire.

The Syrian government said it has begun to withdraw forces ahead of the cease-fire but activists say no significant pullouts have taken place and troops, checkpoints and snipers remain in almost all major flashpoint towns and cities.

"They are systematically trying to crush the revolt wherever they can and regardless of the human cost," said activist Mohammad Saeed in the Damascus suburb of Douma.

US ambassador to Syria Robert Ford said the Syrian government appears to have pulled back some of its forces from towns and cities but in other places has kept in place or simply shifted around troops and armored vehicles. He said he was basing his information on satellite images before and after the alleged pullouts which were posted on the US Embassy Facebook page Saturday.